The Blackguard of the Glen by Michelle Deerwester-Dalrymple

He’s not called Black Douglas for nothing.
In fact, the reason for his name is nothing short of grim.
James Douglas had a heart as black as his name. When his king commands him to wed the daughter of a fallen laird, can the fair Tosia Fraser tame the beast of the Highlands? Discover this stunning Scottish romance today!
James Douglas prides himself on his uncanny military strategy over the English sassenachs, and he soon finds himself at the right hand of King Robert the Bruce of Scotland. But the king and his kinsmen worry that his darker side will consume him.

The king finds an ideal solution. Get the Black Douglas a wife to help ground him and salve his soul.
Tosia Fraser doesn’t know it, but she is the daughter of a powerful laird and staunch ally to the Bruce. To reward the fallen Laird Fraser’s fealty and assure the future of Tosia, the king betroths her to the man whose name strikes fear into the hearts of all who hear it.

The idea of marrying such a beast makes Tosia’s knees weak, but as she gets to know the man behind the beast of Black Douglas, her legs are weak for another reason. When he weds her, James uses his beastly skills to ignite their bed, and Tosia’s heart, on fire.

James Douglas does have a heart, and he swears it to Tosia. It turns out the beast of Scotland can be tamed.
But life is precarious during the Scottish War of Independence, and even though Douglas has led the Scots to a series of victories, this doesn’t mean he will always return to Tosia’s side. Especially when a spy alerts Tosia to a trap laid by the English to kill the Bruce and her Black Douglas.

Armed with this news, Tosia is willing to risk everything, even her own life, to make sure James always returns to her.